Photographic printing apparatus



Oct. 25, 1960 M. H. SUSSIN FHOTOGRAPHIC PRINTING APPARATUS 4Sheets-Sheet 1 Filed June 6, 1958 R N ms mw 5 VS mm W. N H R O F X A A MVACUUM MOTOR PUMP Oct. 25, 1960 M. H. SUSSIN PHOTOGRAPHIC PRINTINGAPPARATUS 4 Sheets-Sheet 2 Filed June 6, 1958 INVENTOR. MAX H. SUSSIN ATORNEYS Oct. 25, 1960 M. H. sussm 2,957,400

PHOTOGRAPHIC PRINTING APPARATUS Filed June 6, 1958 4 Sheets-Sheet 3INVENTOR.

MAX H. SUS SIN K I 't TORNEYS Oct. 25, 1960 M. H. susslN 2,957,400

PHOTOGRAPHIC PRINTING APPARATUS Filed June 6, 1958 4 Sheets-Sheet 4 34 nA I INVENTOR. MAX H. SUSSIN w @M, wm zfw k ATTO RN EYS United StatesPatent PHOTGGRAPHIC PRINTING APPARATUS Max H. Sussin, Chicago, 111.,assignor to Robertson Photo- Mechanix, Inc., Chicago, Ill., acorporation of Illinois Filed June 6, 1958, Ser. No. 740,223

12 Claims. (Cl. 95---76) The present invention relates broadly to theprinting of photographically produced images, and is more particularlyconcerned with a new and improved apparatus for rapidly and effectivelyprinting photographic negatives.

Printing frames of the character wherein the work is located between avacuum blanket and glass frame and exposed to are lights have beenproposed and utilized in Various forms in the past. Each of the devicesof which applicant is aware, however, possesses objections anddisadvantages by reason of being cumbersome, unnecessarily complicated,and not completely reliable. In many constructions an unduly largenumber of latches and locks have been employed in an endeavor toassuresuccessful operation of the apparatus, and the result has beenamechanical assemblage requiring utmost dexterity and patience on thepart of the operator.

It is therefore an important aim of the present invention to provide anovel printing apparatus comprised of a minimum number of readilyfabricated and easily assembled parts.

Another object of the invention lies in the provision of a photographicprinting mechanism operable with ease by a single person and requiring aminimum number of steps and assuring uniform and excellent resultstherefrom.

Another object of this invention is to provide a new and improvedprinting frame construction which is read ily'transportable, and iscomprised of parts constructed and arranged to permit pivotal movementof glass and blanket frames to a printing position with ease and speedand requiring only minimum space for accomplishment of this function.

A further object of the present invention lies in the provision ofprinting apparatus incorporating glass and vacuum blanket framescharacterized in part by a counterbalanced glass frame to facilitate theloading and unloading operation, and wherein the pressure of the glassframe on the blanket frame may be readily adjusted to accommodate a widevariety of work thicknesses without danger of breakage or damagethereto, as Well as to reduce blanket wear and compensate for blanketbeading tolerances.

A still further object of this invention is to provide a photographicprinting device in which a single hand movement by the operatoressentially simultaneously locks the glass frame to the blanket frameand draws vacuum therebetween with the advantageous elimination of thelarge number of latch means and safety locks characterizing the priorart structures.

An even further object of this invention is to provide in apparatus ofthe foregoing character novel means which insures that tipping orrotation of the glass and blanket frames can be accomplished only whenone is locked to the other.

Other objects and advantages of the invention will become more apparentduring the course of the following description, particularly when takenin connection with the accompanying drawings.

In the drawings, wherein like numerals are employed to designate likeparts throughout the same:

Figure 1 is acabinet style printing apparatus embodying the features ofthe present invention;

Figure 2 is a diagrammatic illustration, partly in section, of thevacuum system and associated locking mechanism for the vacuum blanketframe;

Figure 3 is an end view of apparatus constructed in accordance with theprinciples of this invention, with parts broken away to show mechanismfor tilting the glass frame and locking the same to the blanket frame;

Figure 4 is a detail end view illustrating the operation of the levermechanism in locking the glass frame with respect to the'blanket frame;

Figure 5 is a fragmentary sectional view of one form of vacuum blanket;

Figure 6 is an end view of a portion of the apparatus to show thepositioning of parts during tiltable movement of the glass frame;

Figure 7 is a vertical sectional view taken substantially along the lineVIIVII of Fig. 3; and

Figure 8 is a sectional view of another form of air locking mechanism.

Briefly stated, a printing apparatus as constructed in accordance withthe principles of this invention comprises a supporting structurepivotally mounting a vacuum blanket frame to which is hingedly connecteda glass frame floatable thereon. Associated with the glass frame is alinkage pivoted to the supporting structure and actionable under theinfluence of a counter-balance force to permit raising the glass framewith respect to the blanket frame when loading or unloading worktherebetween. A control lever connecting with lever arms is effective tosimultaneously lock the glass frame to the blanket frame and initiatethe drawing of vacuum from between the frames and an unlocking of theblanket frame from the supporting structure. The assembly may then bepivoted about the connection to the structure to expose the work to arelights or the like. Other structural and operational features willbecome apparent during the course of the description now to follow.

Referring now to the drawings, and first to Figures 1, 3 and6 thereof,the printing apparatus of this invention is designated generally by thelegend A and is preferably constructed to include a plurality ofuprights 10 between which extend end walls 11 and front and rear sidewalls 12 and 13, respectively. A four panel construction may of coursebe employed, and in this instance the uprights 10 would be eliminated.Interiorly of the supporting framework provided by the walls anduprights are a plurality of bracing .members 14 positioned as desired torigidify the apparatus. Longitudinally extending bracing members (notshown) may also be provided, and upon one or more of the latter membersadjacent the front wall 12 the vacuum pump and motor arepreferablypositioned. Substantially the entire rear half of the apparatus is freeof interfering structure in order to permit tiltable movement of theglass and blanket frames now to be described.

By locating the vacuum pump and other means upon bracing members, abottom wall is not normally required in the apparatus disclosed.Providing a top wall for the apparatus A when in the closed position ofFigures l and 3 is a frame assembly indicated generally at 15 andcomprising a frame 16 supporting a piece of clear glass 17 and a frame18 to which a vacuum blanket 19 is attached along one surface thereof.As used in the specification and claims, the word glass is intended toinclude all transparent sheet materials as certain plastics aresuitable.

As shown in Figure 5, the blanket 19 preferably comportion 21 of generalY-shape in cross-section.

blanket frame 18 adjacent the rear wall thereof.

The blanket 19 may be fabricated of corrugated rubber and cloth or othersuitable materials, and is attached to the frame 18 by screws, adhesivemeans or in any other desired manner. When the assembly A is closed asin Figures 1 and 3, the glass frame 16 or work is received upon theblanket frame 18 in sealable relation therewith and the Y-shaped portionof the vacuum blanket 19 compressed to effect an air-tight seal. Otherseal constructions may of course be employed.

It is of importance when the glass frame 16 is lowered from the positionof Figure 6 to that of Figure 3, following the positioning of workbetween the glass frame and blanket frame, that substantially allportions of the periphery of the glass frame exert uniform pressure uponthe blanket frame and work located thereon in order to assure a properseal and to avoid damage to the work which may in many instances includea glass plate. For the accomplishment of these purposes, a floatableconnection is provided between the glass frame 16 and blanket frame 18.A form which such a connection may take is shown in Figures 3 and 6, andcomprises a bracket member 22 fixed to the marginalend portions of theThe bracket member 22 may be generally triangularly shaped and providedat one end thereof is a slot 23 receiving a pin 24 spaced inwardly ofthe rear wall of the glass frame and carried by the opposite end wallsthereof. The glass frame 16 is accordingly pivotally connected to theblanket frame 18 by the pin 24 received in the bracket member slot 23,and since this phantom hinge arrangement permits limited verticalmovement of the glass frame with respect to the blanket frame duringlowering of the former unto the latter, constant and uniform pressure isexertedby the glass frame throughout its peripheral contact with theblanket frame.

To expose work or photographic media positioned within the frameassembly 15 to are lights or the like located generally rearwardly ofthe apparatus A, the blanket and glass frames comprising said frameassembly is tilted or rotated to an angle of approximately 90 degrees.To accomplish this movement, which is re quired to prevent deleterioussubstances from the arc lights contacting the glass 17, the blanketframe 1 8 carries at opposite ends generally midway of the width of theframe a pivot pin or the like 25. To accomplish a better balance,however, the pin 25 may be located slightly off the longitudinal centerline of the blanket frame, and in any event, are receivable within aslot 26 (Figure 4) provided in a bracket 27 secured by screws or thelike 28 to the inner surface of each of the side panels 11 of theassembly A. The bracket 27 may be of generally right angular shape inorder to provide clearances for mechanisms later to be described.

To raise or lower the glass frame 16 independently of the blanket frame18, as when loading or unloading work from the frame assembly 15, thereis provided a pivot bracket 29 of the character shown in Figure 7. Thebracket 29 may be cast or otherwise formed to include a pair of spacedpins 30 along one surface receivable in slots 31 provided at oppositeends of the glass frame 16. Provided along the same surface of thebracket 29 and spaced downwardly from the pins '30 is a slot 32 providedto receive one end of the pivot pin 25 carried by the blanket frame 18.The slot 32 is located generally midway of the width of the bracket 29and serves to limit the pressure exerted by the glass frame 16 upon theblanket frame 18 when the frames are locked with respect to one anotherin the manner later to be described. That is, the depth of the slotcontrols the extent of downward travel of the glass frame.

Connecting with pivot bracket 29 by pin means or the like 33 is a pushbar or lever bar member 34. The pin 33 is fixed to the bracket 29 at 35and provides a pivot point for the lever bar 34 during raising orlowering f the glass frame 16. The pin passes through a slot 36 in thelever bar 34 and bears against an adjustment plate 37 having an opening"38 therein receiving the pin 33. The adjustment plate 37 connects withthe lever bar 34 by means of bolts 39 or the like passed through a slot40 in the plate 37 and threaded into an opening 41 in the lever bar 34.By the arrangement described, adjustment may be made to accommodate workof various thicknesses between the glass frame 16 and blanket frame 18without the danger of damage thereto when the glass frame is broughtdown upon the blanket frame. Further, and possibly of even greaterimportance, wear on the vacuum blanket is markedly reduced and there maybe accommodated variations in the cross-sectional thickness of theblanket peripheral portion 21.

The lever bar 34 is connected at one end to the glass frame 16 in themanner above disclosed, and at its opposite end connects with a balancearm 42 by pin means or the like 43. The opposite end of the balance arm42 is pivotally connected at 44 to the framework, either by attachmentto the uprights 10, end panels 11 or a brace 14. The balance arm isprovided along its length with a plurality of openings 45 to control theextent of tension in a counter-balance spring 46 secured at its oppositeend to either an upright 10 or side panel 11. By use of thecounter-balance spring 46 and arms 34 and 42, swingable movement of theglass frame 16 is facilitated and the glass frame 16 held in a semi-openposition when the apparatus is not in use, and thereby wear on thevacuum blanket 19 is reduced.

To draw the glass frame 16 into firm contact with the blanket frame 18,and lock said glass frame to said blanket frame, the lever bar member 34has attached thereto a pin or stud 47 as best shown in Figure 7. Toaccomplish these functions the pin 47 is engaged by book means 48(Figure 4) rigidly connected at 49 to a pivot plate 50 swingably mountedat 51 upon a plate member 52 attached to each of the side panels 11 byscrews or the like 53. Spring means 54 is connected at one end to thehook member 48 and at the opposite end to each side panel 11, andfunctions to hold the hook member in a non-interfering position when theglass frame 16 is raised or lowered independently of the blanket frame18. A roller device 55 of the adjustable type is provided to guide thehook member 48 into engagement with the pin or stud 47 on the lever bar34.

The pivot plate 50 carries a pin connection 56 providing a pivot jointwith a lever arm 57 swingably associated at 58 with a connecting arm 55pinned upon a shaft 60 carried by each of the plates 52 or by the endwalls 11 and extending essentially entirely along the length of theapparatus A. A control handle 61 is also supported by the shaft 60 andtravels in an arc clockwise and counterclockwise to cause rotation ofthe shaft and either locking or release of the glass frame and the otherfunctions to be described.

A mercury switch 62 is mounted upon the shaft 60 for rotation therewithand connections 63 from the switch lead to a motor M showndiagrammatically in Figure 2. A vacuum pump P is operated by said motorand draws vacuum through a line 64 terminating as shown in the vacuumblanket 19. A bleeder connection 65 is provided controlled by a knob 66extending outwardly of the front panel 12 of the apparatus A and locatedin a recess 67 therein. A vacuum indicator 68 is also positioned in thefront wall recess, and by adjustment of the knob 66 on the bleederconnection, vacuum pressure may be regulated and the desired degree ofvacuum drawn through the line 64.

Connecting also with the vacuum blanket 19 is a line 69 terminating inan air lock device 70. The device 70 may be of any desired construction,and a preferred structural arrangement comprises a cylinder 71 having abase plate 72 at one end and a top plate 73 at the opposite endreceiving the vacuum line 69. Movable within the cylinder'71 is a piston74 supported upon a shaft 75 and backed by a cup 76 and washer 77. Aspring 78 bears at one end against the washer 77 and at its opposite endagainst a wall of the top plate 73. A gasket 79 may be provided toeifect proper sealing of the parts.

The shaft 75 is shaped to include a relatively slender portion 80 and arelatively thicker portion 81, and at one end of the relatively lesserdiameter portion 80 of the shaft 75 is a knob 82. A plate 83 dependsdownwardly from the blanket frame 18 and said plate is provided with akeyhole slot 84 opening with its larger portion along the lower edge ofthe plate 83. As is now apparent, the spring 78 causes the relativelylarger diameter portion 81 of the shaft 75 to bear against the smallerportion of the keyhole slot to lock the blanket frame to the supportingstructure. By pressing inwardly on the knob .82, or drawing vacuumthrough the line 69 from the air lock device 75], the shaft 75 will moveinwardly to permit the relatively smaller and relatively larger portionsof the keyhole slot 84 to be passed upwardly from the reduced port-ion80 of the shaft 75 to release the blanket frame 18 from supportingstructure. The design of the air lock 70 and the vacuum pressure are ofcourse, controlled to assure that the blanket frame will not be releasedfrom supporting structure until sufiicient vacuum has been drawn toproperly hold the work against the vacuum blanket 19 when the frameassembly 15 is tipped into a vertical position. Further, as will bedescribed hereinafter, when the vacuum is released the force of thespring 78 in the air lock will again secure the larger diameter portion8 1 of the shaft '75 against the smaller portion of the keyhole slot 85and thereby lock the blanket frame to the supporting structure.

To facilitate tiltable movement of the glass frame 16 about the pivotalconnection 23 and 24 with the blanket frame 18, as when inserting orremoving Work from between the two frames, a handle or equivalent means85 is provided along the front wall of the glass frame 16. Further, toaccommodate the lever bar member or push bar 34 during the noted tiltingmovement, the printing apparatus A is provided with openings 86 atopposite ends thereof.

The operation of applicants new and improved printing apparatus may bedescribed as follows. The blanket frame 18 is normally secured by thedescribed air lock device 7! and plate 83 to supporting structure, andwhen in this secured position the operating lever 61 is moved clockwiseor rearwardly to disengage the hook member 48 from the pin or stud 47 onthe push bar 34 and thereby effect a release of the glass frame 16 fromthe blanket frame 18. The glass frame is thereupon raised, preferably bygrasping the handle 85, and during this movement the balance bar 42proceeds upwardly about the pivot point "44 to swing the push bar 34diagonally rearwardly about the pivot connection 43, raising the glassframe about its pivotal connection 23 and 24 with the blanket frame 18.During said upward and diagonally rearward movement of the push bar, theupper end thereof pivots to a minor degree about the pin connection 33.

The work to be printed, which may be in the form of a plate andnegative, is then positioned upon the vacuum blanket 19 of the blanketframe 18 and the glass frame 16 lowered into position. The slot 32 ofthe pivot bracket 29 connected to the glass frame is at this timereceived upon or about the pivot pin 25 carried at opposite ends of theglass frame 18, said pin 25 being permanently received within the slots26 in each of the brackets 27. The operating handle 61 is then rotatedcounterclockwise or rearwardly, and during this motion of the handle,the locking mechanism proceeds through the position indicated in Figure4 by the direction of arrows and by the dotted lines thereon.Counter-clockwise movement of the control lever 61 causes correspondingrotation of the shaft 60 and connecting lever '59 thereon. The lever 59proceeds rearwardly and downwardly through a limited arc, and by virtueof the pivot connection 58 to a lever arm 57, the latter arm issimilarly moved rearwardly and downwardly in the manner indicated inFigure 4. The connection 56 between the pivot plate 56 and lever arm 57induces an upward or clockwise travel of the pivot plate 50 about therigid pivot 51 fixed to the plate 52. As the plate 50 rotates upwardlythe hook member 48 is drawn downwardly and rearwardly in rolling contactwith the guide roller 55 to engage the hook member with the stud or pinon the push rod 34 and draw said rod downwardly to lock the glass frame16 against the blanket frame 18 in the positions illustrated in Figures3 and 7. It is to be particularly noted that during the final phase ofpush rod movement, said rod travels in a true vertical direction andthereby there is no shifting of the glass frame relative to the blanketframe.

Essentially simultaneously with the locking action described, rotationof the shaft 60 causes tipping of the mercury switch 62 to start themotor M and begin operation of the vacuum pump P. Vacuum is thereupondrawn from the blanket 19 through the line 64 and through the line 69 torelease the shaft 75 of the air lock 70 from the plate 83 on the blanketframe 18. The frame assembly 15 comprising the glass frame 16 andblanket frame 18 with the work positioned therebetween may then berotated or swung on the blanket frame pivot pins 25 carried in the slots26 of the brackets 27. The hook 48 during the tilting of the frameassembly 15 of course remains in engagement with the stud 47 on the pusharm or lever 34. The frame assembly 15 is rotated or pivotedapproximately degrees in a clockwise direction to locate the frameassembly generally vertically or in an upright position in order topermit exposure of the work to arc lights or the like positionedgenerally rearwardly of the printing apparatus A.

After exposure of the work therein, the frame assembly 15 is restored toa horizontal position and the operating lever 61 moved clockwise orrearwardly to turn off the vacuum pump and motor. This causes the lanketframe 18 to be locked to the supporting structure by action of the airlock 70, and rotation of the shaft 60 releases the hook 48 from the studor pin 47 on the push rod 34. With the glass frame 16 thus unlocked fromthe blanket frame 18, said glass frame may be pivoted upwardly as shownin Figure 6 to permit removal of the exposed work. Disengagement of thehook 48 from the stud or pin 47 occurs by reason of the movement of theparts shown in .dot-and-dash lines in Figure 4.

If desired, an air locking mechanism of the character shown in Figure 8may be employed in substitution for the device 7 of Figure 2. Designatedgenerally by the numeral 87, the construction of Figure 8 is of thediaphragm type and includes a top plate 88 having a radial bore 89communicating at one end with a hose connection 90 and at the oppositeend with an axial bore 91 bottoming a spring 92. The spring connectswith one end of a shaft 93 supporting a collar 94 receiving a. diaphragm95 secured at its periphery by a housing or cylinder 96- which may be ofa two part construction. The shaft travels axially in a bushing 97carried in a base plate 98 aper-tured at 99. The knob 82a and shaftportions 89a and 81a are essentially the same as in the form of Figure2, to permit locking and unlocking with the plate 83a as earlierdescribed. It will now be apparent that by drawing vacuum through thebores 89 and 91 and through the connection 90, diaphragm movement ingenerally its central portion to the right or rearwardly will occur tocause axial travel of the shaft 93 and release of said shaft from thekeyhole slot 84a of the plate 83a on the blanket frame 18.

It may be seen from the foregoing that applicant has provided a novelprinting apparatus characterized by relative simplicity of operationpermitted by a new and improved arrangement of a number of readilyfabricated and assembled parts. The mechanism locking the glass frame tothe blanket frame is rapid acting, and being constructed of leverlinkages, assures that malfunctions will be essentially entirely absenttherefrom.

arrangement locking the blanket frame to the supporting structure, it isessentially impossible .to tip the blanket .frame when the glass frameis not secured thereto. The apparatus may be readily operated by asingle person and consistently uniform results obtained from itsoperation.

It is to be understood that the form of the invention therein shown anddescribed is to be taken as the preferred embodiment of the same, andthat various changes in the size, shape and arrangement of parts may beeffected without departing from the spirit of .the invention or thescope of the subjoined claims.

I claim as my invention: 1. Apparatus for printing photographic media,comprising a supporting framework, a vacuum blanket frame pivotallysupported on said framework, a glass frame supported for tiltablemovement with respect to the blanket frame to permit loading andunloading of the media therebetween, means for securing the glass frameto the blanket frame to prevent separation of said frames during pivotalmovement thereof, means connecting the blanket frame to a source ofvacuum, means locking the blanket frame to the supporting framework whenthe glass frame is unsecured to the blanket frame, and means vconnectingthe blanket frame to the locking means and providing release of theblanket frame from the supporting framework when the vacuum pressure hasreached a predetermined point.

2. Apparatus for printing photographic media, comprising a supportingframework, a vacuum blanket frame pivotally supported on said framework,a glass frame pivotally connected at opposite ends to the blanket frameand adjustably swingable relative thereto to permit loading andunloading of the media between said frames, means for securing the glassframe to the blanket frame to prevent separation of said frames duringpivotal movement thereof, said means comprising a linkage actuatedmember drawing the glass frame into continuous contact 'with the blanketframe and maintaining the same thereon, means connecting the blanketframe to a source of vacuum, means locking the blanket frame to thesupporting framework when the glass frame is unsecured to the blanketframe, and means connecting the blanket frame to the locking means andproviding release of the blanket frame from the supporting frameworkwhen the vacuum pressure has reached a predetermined point.

3. Apparatus for printing photographic media, comprising a supportingframework, a vacuum blanket frame pivotally supported on said framework,a glass frame supported for tiltable movement with respect to theblanket frame to permit loading and unloading of the media therebetween,means for securing the glass frame to the blanket frame to preventseparation of said frames during pivotal movement thereof, meansconnecting the blanket frame to a source of vacuum, means locking theblanket frame to the supporting framework when the glass frame isunsecured to the blanket frame, said means comprising an air lock deviceprovided with a movable shaft and a plate member having a keyhole slottherein receiving said shaft and lockable therewith, and meansconnecting the blanket frame to the air lock device and providingrelease of the shaft thereof from the plate member when the vacuumpressure has reached a predetermined point.

4. Apparatus for printing photographic media, comprising a supportingframework, a vacuum blanket frame pivotally supported on said framework,a glass frame supported for tiltable movement with respect to theblanket frame to permit loading and unloading of the media therebetween,means for securing the glass frame to the blanket frame to preventseparation of said frames during pivotal movement thereof, said meansincluding a lever member pivotally associated with the supportingframework and carrying a pin thereon, and a swingable hook memberengageable with the pin and drawing the glass frame into continuouscontact with the blanket frame and maintaining the same thereon, meansconnecting the blanket frame to a source of vacuum, means locking theblanket frame to the supporting framework when the glass frame isunsecured to the blanket frame, and means connecting the blanket frameto the locking means and providing release of the blanket frame from thesupporting framework when the vacuum pressure has reached apredetermined point.

5. Apparatus for printing photographic media, comprising a supportingframework, a vacuum blanket frame pivotally supported on said framework,a glass frame supported for tiltable movement with respect to theblanket frame to permit loading and unloading of the media therebetween,a lever member connected at one end to the glass frame and pivotallyassociated with the supporting framework at its opposite end andswingable vertically and diagonally to tilt the glass frame about itssupport with the blanket frame, a hook member associated with theframework and cooperating with the lever member to draw said member andglass frame downwardly and lock the glass frame in continuous peripheralcontact with the blanket frame, means connecting the blanket frame to asource of vacuum, air actuated locking means engageable with the blanketframe and securing the same to the supporting framework when the hookmember is disassociated from the lever member, and means to load andunload the media therebetween, a lever member connected at one end tothe glass frame and carrying a pin thereon, a rotatable shaft supportedby the framework, a linkage connected to the shaft and carrying a pinengaging member efiective upon rotation of the shaft to contact thelever pin and draw the glass frame into locked engagement with theblanket frame to prevent separation of said frames during pivotalmovement thereof, means connecting the blanket frame to a source ofvacuum, and means locking the blanket frame to the supporting frameworkwhen the glass frame is unsecured to the blanket frame, said lockingmeans being operable upon shaft rotation in one direction to lock theblanket frame to the framework and upon shaft rotation in anotherdirection to release said frame from said framework to permit pivotalmovement thereof into a printing position.

7. Apparatus for printing photographic media, comprising a supportingframework, a vacuum blanket frame pivotally supported adjacent itscenterline on said framework for rotation therein to an essentiallyvertical position during printing of the media, a glass frame supportedfor tiltable movement with respect to the blanket frame to load andunload the media therebetween, a lever memher connected at one end tothe glass frame and carrying a pin thereon, a rotatable shaft supportedby the framework, a linkage connected to the shaft and carrying a pinengaging member effective upon rotation of the shaft to contact thelever pin and draw the glass frame into locked engagement with theblanket frame to prevent separation of said frames during pivotalmovement thereof, means connecting the blanket frame to a source ofvacuum, and means locking the blanket frame to the supporting frameworkwhen the glass frame is unsecured to the blanket frame, said lockingmeans comprising an air operated cylinder and a piston thereinsupporting a shaft, and a plate member having a slot therein receivingthe shaft of said piston, the shaft supported by the framework beingoperable when rotated in one direction to actuate the linkage and lockthe glass frame to the blanket frame and after a predetermined periodrelease the piston shaft from the plate member slot to permit pivotalmovement of the blanket frame into a printing position.

8. In combination with a vacuum blanket supporting frame and glasssupporting frame pivotally mounted upon a framework, the improvementwhich comprises a source of vacuum, means connecting the vacuum sourceto the vacuum blanket, locking means on the framework connecting withthe blanket, and plate means on the blanket supporting frame having aslot therein, said locking means comprising a cylinder, a piston movabletherein and carrying a shaft, and a spring in said cylinder normallyurging the shaft into locking engagement with the slot in the platemeans, said locking and plate means securing the blanket frame to theframework until a predetermined vacuum pressure has been drawn betweenthe blanket and glass frames and thereupon releasing the blanket frameto permit pivotal movement thereof.

9. Apparatus for printing photographic plates and the like, comprising acabinet structure including side and end walls, a frame assembly adaptedto close the top of said cabinet and comprised of a blanket framepivotal- 1y carried at opposite ends by the cabinet end walls and aglass frame floatably mounted upon the blanket frame and pivotablerelative thereto, a bar member connected at one end to the glass frameto raise and lower the same independently of the blanket frame, a leverarm pivotal- 1y joined to the cabinet and connecting at its opposite endto the bar member to swing said member vertically and diagonally duringpivotal movement of the glass frame, a locking mechanism connecting theglass frame to the blanket frame to prevent separation of said framesduring tilting thereof, vacuum means connecting with the blanket frame,an air locking mechanism securing the blanket frame to the cabinet andconnecting with the vacuum means to release the frame from the cabinetwhen vacuum pressure has reached a predetermined point, and a levermechanism connecting with the first locking mechanism and effective uponmovement to lock the glass frame to the blanket frame and causeoperation of the vacuum means and release of the blanket frame from thecabinet.

10. Apparatus for printing photographic plates and the like, comprisinga cabinet structure including side and end walls, a frame assemblyadapted to close the top of said cabinet and comprised of a blanketframe pivotally carried at opposite ends by the cabinet end walls and aglass frame fioatably mounted upon the blanket frame and pivotablerelative thereto, a bar member connected at one end to the glass frameto raise and lower the same independently of the blanket frame, said barmember carrying pin means thereon, a lever arm pivotally joined to thecabinet and connecting at its opposite end to the bar member to swingsaid member vertically and diagonally during pivotal movement of theglass frame, a looking mechanism connecting the glass frame to theblanket frame to prevent separation of said frames during tiltingthereof, said locking mechanism including hook means engageable with thepin means lowering and locking the glass frame upon the blanket frame,vacuum means connecting with the blanket frame, an air locking mechanismsecuring the blanket frame to the cabinet and connecting with the vacuummeans to release the frame from the cabinet when vacuum pressure hasreached a predetermined point, and a lever mechanism connecting with thefirst locking mechanism and effective upon movement to lock the glassframe to the blanket frame and cause operation of the vacuum means andrelease of the blanket frame from the cabinet.

11. Apparatus for printing photographic plates and the like, comprisinga cabinet structure including side and end walls, a frame assemblyadapted to close the top of said cabinet and comprised of a blanketframe pivotally carried at opposite ends by the cabinet end walls and aglass frame floatably mounted upon the blanket frame and pivotablerelative thereto, a bar member connected at one end to the glass frameto raise and lower the same independently of the blanket frame, a leverarm pivotally joined to the cabinet and connecting at its opposite endto the bar member to swing said member vertically and diagonally duringpivotal movement of the glass frame, a locking mechanism connecting theglass frame to the blanket frame to prevent separation of said framesduring tilting thereof, vacuum means connecting with the blanket frame,an air lock device on one of the cabinet walls, plate means on theblanket frame releasably engaged by the air lock device, a rotatableshaft extending between opposite end walls of the cabinet and connectingwith the locking mechanism, and an operating lever rotating said shaftto lock the glass frame to the blanket frame and cause operation of thevacuum means and release of the air lock device from the plate means.

12. In combination with a vacuum blanket supporting frame and glasssupporting frame pivotally mounted upon a framework, the improvementwhich comprises a source of vacuum, means connecting the vacuum sourceto the vacuum blanket, locking means on the framework conmeeting withthe blanket, and plate means on the blanket supporting frame having aslot therein, said locking means comprising a housing, a shaft movableaxially with respect to the housing, a diaphragm supported by the shaftand housing, and a spring in the housing normally urging the shaft intolocking engagement with the slot in the plate means, said locking andplate means securing the blanket frame to the framework until apredetermined vacuum pressure has been drawn between the blanket andglass frames and thereupon releasing the blanket frame by axial movementof the locking means shaft to permit pivotal movement of said blanketframe.

References Cited in the file of this patent UNITED STATES PATENTS2,117,051 Anderson May 10, 1938 2,494,282 Campbell Jan. 10, 19502,594,920 Halpern Apr. 29, 1952 2,718,181 Gullixson Sept. 20, 1955

